Top 10 Undertale Bosses

The Top Ten
1 Sans Sans or Sans the Skeleton is a character in the 2015 RPG Undertale created by Toby Fox. He is a lazy, pun-loving skeleton who is a supporting protagonist in the "pacifist" and "neutral" routes of Undertale, and a heroic antagonist/final boss of the "genocide" route. He is known for his incredibly difficult ...read more.

This is the hardest boss fight I ever had in my entire gaming experience. All of its attacks is hard but the hardest attack is the final attack (not the special attack), like how on earth do you do the spiral gaster blaster? so this character deserves my vote.

Definitely the hardest boss in the game (that takes probably at least 20 or 30 tries to beat the first time) and the one with the best gameplay, with lots of different attacks that require a lot of skill and some pretty good reflexes. Also, Sans is one of the best characters in the game, and being forced to kill him is kind of heartbreaking, specially with all his dialogue throughout the fight. It's an emotional and stressful ride that we won't be forgetting so soon.

A massively powerful monster. I'm mean he can throw about 1,000,000 bones, fire deadly gaster blaster, use telekinesis (not referring to Pokemon move) poisons you with karmic retribution, can teleport, can break the 4th wall and FREEZE TIME! I rank him 3rd most powerful undertale character. But is still very carefree and lazy telling bad puns. I also love his battle song.

Such a troll and the theme is so awesome I could listen to it for 10 weeks straight. I'm a lot like him too. I'm lazy and I can't stop making bad puns. I've listened to multiple versions of the song and all are rated over 1 million!

2 Mettaton Mettaton is a character in the popular 2015 RPG game, Undertale. He is a robot with a soul built by Dr. Alphys, and is the sole television star of the underground. Mettaton is a popular character in the fanbase. His notable features include his legs, and his catchphrase "OH YESSSS!"

Mettaton is probably the funniest character in the whole game, and his final battle is certainly his climax. Starring his beautiful new body, Mettaton EX is the perfect combination of fun gameplay and funny moments and dialogues, and is also one of the most creative moments in Undertale (the idea of an audience score during the fight is brilliant)

All right! I think we were all expecting Sans but I definitely think Mettaton is the best. He also has by far the best theme song and of course the best legs.

This boss fight is great! I enjoyed the plot twist during the battle intro, the music, and Mettaton himself.

,I was half expecting to see sans here but its Mettaton! I think he deserves this place because on the pacifist run he has two forms,in genocide he has 3.

3 Asriel Dreemurr Asriel Dreemurr is a character from the 2015 game "Undertale". He was created by Toby Fox. ...read more.

Top ten boss fights. Not top ten hardest boss fights. The only way to win is not sparing him, but saving him. His track is one of the best in the game. I'm talking about His Theme. A complete masterpiece that deserves better than in some sad comics and animation that don't have anything to do with asriel, or flowey. Also he has the sadest backstory in the game, second being Chara. He is the most powerful boss in the entire game, (He has the power of seven humans, and can erase existence) and the fight is one of the most epic in the game. Saving someone who seemed irredeemable, but definitely wasn't.

This fight is great in almost every way. It's super epic, emotional and dramatic, making this the perfect climax for the game. The only thing that bothers me about this battle is it's too easy, which makes it kind of underwhelming at some points, but it's still an amazing experience because of the characters and emotions involved and the AWESOME soundtrack.

Of the final bosses, Sans is #1. Of course. Why. But Asriel Dreemur is an epic boss to end the hard Pacifist run, which forces you onto only 20 health, and low stats. And his boss theme is o h s o e p I c!

He's not very hard since you really can't lose, but he's the boss that'll probably pull on your heartstrings the most, only behind Asgore.

4 Photoshop Flowey

I couldn't possibly have chosen any other boss battle for the 1st spot. This fight is the perfect final battle for the game: it's hard, it's disturbing (whoever thought about making Omega Flowey a Photoshoot abomination is a genius), it's fun and it's EPIC in a whole new level. The soundtrack is amazing and it fits so well in the fight that it's almost like they made it first and then created a boss battle to fit in it! Also, making Flowey able to load save files and close your game during the fight makes it so much disturbing and scary, it's just brilliant. It's not the most emotional fight in the game, neither it has the best gameplay, but the whole feeling of despair and eventually epicness makes it so satisfying and memorable, and the sudden change of graphics makes it really unique.

I sometimes wonder what Toby Fox was on when designing this boss. Like... no sane person or someone not doing drugs would create this. There is no way.

Is scary, it gives you a sense of what Flowey can really do. With no Asriel in the way, it is evil and dark. Exactly what the game truly is.

You know, Photoshop flowey AKA, Omega Flowey is really OP, I also like sans, even though he dodges attacks. both Omega Flowey and Sans are really good.

5 Asgore Dreemurr Asgore Dreemurr is a boss monster and the king of the monsters in the 2015 RPG Undertale made by Toby Fox. Asgore is the portrayed main antagonist who plans to acquire seven human souls and use their power to break the barrier that seals the monsters underground . Aspects of his character are hinted ...read more.

This is a boss that is not only difficult, it's a pretty emotional one. He's reluctant to fight, he can't even look at you in the eye, the music fills the atmosphere, his attacks weaken as your HP lowers, etc. enough said.

The epic opening, breaking mercy, forced to fight the kindest monster in the underground, his final words, the bitter end. no other boss represents Undertale better than Asgore

I legit got stuck on this battle for like a month because I ran out of food and it's so hard without consumables...

Undertale the game that makes you feel awfull for killing anything! But this was just worst. Asgore is my favorite and I didn't want to kill him
Stupid flower

6 Papyrus Papyrus is a character from the 2015 game Undertale, made by Toby Fox. He is the Younger brother of Sans the skeleton, royal guard in training, and a sentry in the town of Snowdin. Opposite to his brother, papyrus is active, loud, and full of himself; but in an endearing way. Papyrus means to become ...read more.

I truly love the Papyrus boss fight. Bonetrousle is one of my favorite pieces of music in Undertale and it's an extremely funny fight, especially considering that his dialogue is some of the funniest. What I truly love about Papyrus is that he refuses to kill anyone, which is one of the most sweetest things in any game... EVER! Well done, Toby Fox, for such an original character.

I really love this boss fight because its easy and fun! its pretty amusing and there are a lot of jokes in there - and it gets even better if you decide to flirt with papyrus! you don't even really need to do anything, as you can just die three times and precious cinnamon roll papyrus will spare you anyway. he just can't bear to hurt you, aww

Papyrus is my favorite caricature in the game! And I got to saw that when I saw his boss fight it was funny and the dating thing was hilarious,but there are better fights in the game.

If someone can't beat him, he just spared you after 3 tries. And if you're doing a no death run, he is not a risk.

7 Undyne the Undying Undyne is a main character in Toby Fox's 2015 RPG, Undertale. She is the heroic fishlike captain of the Royal Guard, who takes it upon herself to protect the monsters of the Underground. Her name is derived from the word "Undine", and is a pun on the word "Undying". Her most loved monsters are her mentor, ...read more.

Here's the second hardest boss in the game, and the one that tried to warn us about how frustrating the path we were taking was going to be. The introduction to this fight is really awesome and unexpected, because every other character you faced up to this point were instantly killed with one hit. But not Undyne. She just refused to die.

Let's face it. I can't vote for sans because I have fought him yet. And do you know why? Because I can't get past Undyne. I mean, this boss fight is an amazing fight to get stuck on and then to curl up into a ball of despair because I can't beat it.

The boss whose theme warns you: there's a difference between protagonist and hero.

This fish lady is the 2nd hardest boss I have ever faced in a video game!

8 Muffet Muffet is a character from the game Undertale. She appears in a region called Hotland, selling pastries to raise money to rent a heated limo to help the spider clan from the Ruins (who are also raising a bake sale) reunite with the one in Hotland because the spiders can't cross Snowdin.

Her song is one of the best I've heard in this game, her fight is innovative, it's fairly challenging, enough said.

You can even skip this battle. The YouTuber I watched skipped it, and I usually HATE spiders, but today I did some research...

Best boss

Truly amazing song and plot. COuldn't be harder/better for the game.

This is pretty dang challenging without a Spider Donut...

9 Toriel

She's definitely one of the easiest bosses, but also one of those bosses that can really pull on your heartstrings.

10 Alphys NEO
The Contenders
11 Mad Dummy

This thing just looks funny, has great music, and overall is a really fun and hilarious boss fight. I love its attacks.

I have bone to pick with people who think sans is the best. Awesome battle theme too.

Probrably the most original fight, because you have to use his own attacks against him to beat him.

Underrated boss. One of the hardest.

12 Undyne Undyne is a main character in Toby Fox's 2015 RPG, Undertale. She is the heroic fishlike captain of the Royal Guard, who takes it upon herself to protect the monsters of the Underground. Her name is derived from the word "Undine", and is a pun on the word "Undying". Her most loved monsters are her mentor, ...read more.
13 Greater Dog

All of the dogs in the game are so cute!

Just throw a stick. Done.

14 Snowdrake's Mother
15 Gaster

Hidden boss hard to beat

16 Napstablook Napstablook is a secondary character from Toby Fox's 2016 RPG, Undertale. He is the cousin of Mettaton, who left him in order to become famous. Due to this, poor Blooky has crippling depression.
17 Mettaton NEO

He attacks if theres an audience and if you do nothing in the fight

He looks cool...

18 Reaper Bird
19 Mad Mew Mew

A psychotic training dummy has become... An anime girl? This is a happy twist for Mad Dummy (assuming you spare Mew Mew), as if you talk to her later, you'll find that she's becoming more like the character that she appears as, and less like, well, Mad Dummy.

20 Chara Chara is a character in the game Undertale by Toby "Radiation" Fox who is one of the seven people to fall to the Underground prior to the fall of the player character. Their name can be changed by the player and will be assumed as the player character, until the Pacifist Route when Asriel asks for the ...read more.
21 Memoryhead
22 Lesser Dog Lesser Dog is a character from Undertale. He is part of the Snowdin Canine Unit, and is famous for his long neck.
23 Endogeny

This was creepy...

24 Lemon Bread

His name is all you need.

25 So Sorry
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